Meiosis

Figure 9 shows a human egg cell viewed using a light microscope.

In Figure 9, the diameter of the image of the egg is 38 mm.

The magnification of Figure 9 is × 400

Calculate the real diameter of the egg cell in micrometres.

Use the equation:

1 millimetre = 1000 micrometres

Real diameter of egg cell = _____________________ micrometres

Draw a simple diagram of the egg cell shown in Figure 9.

On your drawing:

$l~bel two parts of the egg cell that are visible in Figure 9

$do not include other cells.

Some parts of a human egg cell are not visible in Figure 9.

Name one part of a human egg cell that is only visible using an electron microscope.

Name the process of cell division that produces egg cells.

How many chromosomes are in a human egg cell?

Describe how a chromosome in a sperm cell determines whether the offspring that forms is male or female.

Which hormone stimulates the release of an egg?

Tick () one box.

FSH

LH

Oestrogen

Oral contraceptive pills contain hormones that prevent the release of an egg.

Scientists studied the effectiveness of different types of contraception with perfect use and with use in real life.

‘Perfect use’ means following all the instructions.

‘Use in real life’ is what actually happens in the population. The instructions may not always be followed in real life.

Figure 10 shows the results.

Evaluate the effectiveness of the three types of contraception shown in Figure 10.

Use data from Figure 10.

Figure 1 shows a human egg cell viewed using a light microscope.

In Figure 1, the diameter of the image of the egg is 38 mm.

The magnification of Figure 1 is × 400

Calculate the real diameter of the egg cell in micrometres.

Use the equation:

1 millimetre = 1000 micrometres

Real diameter of egg cell = _____________________ micrometres

Draw a simple diagram of the egg cell shown in Figure 1.

On your drawing:

$l~bel two parts of the egg cell that are visible in Figure 1

$do not include other cells.

Some parts of a human egg cell are not visible in Figure 1.

Name one part of a human egg cell that is only visible using an electron microscope.

Name the process of cell division that produces egg cells.

How many chromosomes are in a human egg cell?

Describe how a chromosome in a sperm cell determines whether the offspring that forms is male or female.

Which hormone stimulates the release of an egg?

Tick () one box.

FSH

LH

Oestrogen

Oral contraceptive pills contain hormones that prevent the release of an egg.

Scientists studied the effectiveness of different types of contraception with perfect use and with use in real life.

‘Perfect use’ means following all the instructions.

‘Use in real life’ is what actually happens in the population. The instructions may not always be followed in real life.

Figure 2 shows the results.

Evaluate the effectiveness of the three types of contraception shown in Figure 2.

Use data from Figure 2.

Figure 7 shows an oak tree.

The binomial name of the oak tree is Quercus robur.

What is the genus name of the oak tree?

Tick (✓) one box.

Oak

Quercus

Robur

Other species of tree are in the same genus as Quercus robur.

What does it mean if two species of tree are in the same genus?

Tick (✓) one box.

The two species are always found in the same place.

The two species are closely related to each other.

The two species look exactly the same.

Oak trees grow at points where cells can divide.

Growth in oak trees happens at the tips of the branches.

Name the type of tissue at the tips of the branches.

Oak trees reproduce by sexual reproduction to produce seeds.

An acorn is a nut that contains a seed.

The seed may become a new oak tree.

Which process produces the cell that grows into the seed?

Tick (✓) one box.

Evolution

Fertilisation

Translocation

One type of insect lays eggs in acorns.

The insect eggs cause the acorn to grow abnormally.

The abnormal growth is called a gall.

Insect embryos grow inside the gall.

Figure 8 shows a normal acorn and an acorn that has grown a gall.

The gall is made from oak tree cells that have divided.

The cells of the gall contain two sets of chromosomes.

Which process produces the cells of the gall?

Tick (✓) one box.

Circulation

Digestion

Mitosis

The insects have changed over time and caused a gall to grow on acorns.

The gall increases the chance of survival of the insects inside the gall.

What name is given to the process of the insects changing over time?

Tick (✓) one box.

Clone production

Evolution

Inbreeding

The oak tree transports water and nutrients to the insect embryos inside the gall.

Enlarge

Water moves from the roots to the leaves.

Name the process that moves water from the roots to the leaves.

This question is about plant tissues.

Plant meristem tissue is found in the growing tips of shoots and roots.

Name two processes in plants that only occur in meristem tissue.

An acorn is a nut that contains the seed of an oak tree.

When one type of insect lays an egg in an acorn, the acorn grows abnormally.

The abnormal growth is called a gall.

An insect embryo grows inside the gall.

Figure 8 shows a normal acorn and an acorn that has grown a gall.

The seed in an acorn forms from one original cell with two sets of oak tree chromosomes.

The original cell in each seed was produced by sexual reproduction.

The gall has cells that contain two sets of oak tree chromosomes.

Compare the process that produced the original cell in each seed with the process that produced cells in the gall.

The insect embryo inside the acorn:

causes the growth of the gall

uses nutrients from the gall to grow

causes lignin to form around the outside of the gall.

The lignin around the gall protects the acorn from being eaten by herbivores.

Which other structure in the oak tree contains lignin?

Tick (✓) one box.

Phloem

Root hair cells

Xylem

Many years ago, a mutation of an insect embryo led to the embryo causing lignin production in an acorn.

Explain how the mutation could have produced a population of insects that all cause lignin production.

This question is about hormones.

Draw one line from each hormone to the function of that hormone.

In one menstrual cycle, an egg is released on day 13.

Which chemical causes the egg to be released?

Tick (✓) one box.

Cholesterol

Insulin

Lipase

Luteinising hormone

Hormones are used in some methods of contraception.

Which two types of contraception use hormones?

Tick (✓) two boxes.

Condom

Diaphragm

Oral contraceptive pill

Skin patch

Surgical sterilisation

Figure 5 shows how a baby is formed.

Use Figure 5 to answer questions 04.4 to 04.6.

Name the process happening at A.

The sperm and egg were formed by meiosis.

Meiosis is a type of cell division.

Name the type of cell division happening at B.

At C the cells are stem cells.

Explain how the stem cells become cells that can carry nervous impulses.

Figure 4 shows a mosquito on human skin.

Malaria is a communicable disease.

Mosquitos can transmit malaria when they bite.

What is a communicable disease?

Tick (✓) one box.

Humans have adaptations to defend the body against pathogens.

Draw one line from each body part to the adaptation that defends against pathogens.

What type of chemical is used to kill mosquitos?

Tick (✓) one box.

Scientists are trying to reduce the number of people developing malaria by using genetically modified (GM) mosquitos.

Mosquitos have 6 chromosomes in each normal body cell.

How many chromosomes are in each egg cell from a mosquito?

Tick (✓) one box.

Which statement describes genetic modification?

Tick (✓) one box.

GM mosquitos can be produced in large numbers in laboratories.

These GM mosquitos can be released to reduce the population of wild mosquitos.

What is one advantage of using GM technology to reduce the population of wild mosquitos?

Tick (✓) one box.

A plant shoot is made of several tissues.

What is a tissue?

Tick (✓) one box.

What is the name of the tissue at the growing tip of a plant shoot?

Tick (✓) one box.

Plant cells divide by mitosis so that the plant can grow.

Give one other reason plant cells divide by mitosis.

Do not refer to growth in your answer.

Figure 9 shows a cell cycle.

Which two processes happen during cell growth in the cell cycle?

Tick (✓) two boxes.

In mitosis and meiosis cells divide to produce new cells.

Cell division by meiosis produces gametes.

Figure 10 shows a cell dividing by mitosis and a different cell dividing by meiosis.

Describe how the cells produced by mitosis are different from the cells produced by meiosis.

Use information from Figure 10.

A scientist investigated cell division in the growing tip of a plant shoot.

The scientist recorded data at different distances from the tip of the shoot.

Table 6 shows the results.

Give two conclusions from the data in Table 6.

Bananas from wild banana plants are not eaten by humans.

Edible banana plants are grown commercially.

Humans can eat bananas from edible banana plants because they do not contain seeds.

The edible banana plant evolved from the wild banana plant.

Figure 12 shows how scientists think the edible banana plant may have evolved.

What is process X in Figure 12 ?

Tick (✓) one box.

Explain why the edible banana plant cannot produce gametes.

Cloning is used to reproduce edible banana plants.

The cloned cells divide by mitosis.

Describe the process of mitosis.

Banana plants can become infected by the TR4 fungus.

The fungus enters the plant through the roots and grows within the xylem vessels.

The xylem vessels become blocked and the leaves turn yellow.

Describe why blockage of the xylem vessels causes the leaves to turn yellow.

TR4 fungus is a threat to the global banana industry.

Some wild banana plants have a gene for resistance to the TR4 fungus.

What could scientists do to protect edible banana plants from the TR4 fungus?

Tick (✓) one box.