Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

B5 Homeostasis and Response/B6 Inheritance, Variation and Evolution > B5 Homeostasis and Response/B6 Inheritance, Variation and Evolution random revision (pages 58-81) > Flashcards

B5 Homeostasis and Response/B6 Inheritance, Variation and Evolution random revision (pages 58-81) Flashcards

1
Q

Name the process responsible for regulating conditions inside the body to maintain a stable internal environment?

A

Homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the function of the receptor in an automatic control system?

A

To detect stimuli (changes in the environment).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which component, X, is missing from this flowchart of a control system? Name the component and describe its role?

Receptor detects a stimulus
V
V

       X

       V
       V

Effector produces a response to restore optimum levels

A

The coordination centre, which receives and processes the information then organises a response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What term is given to the system in vertebrates made up of the brain and apinal cord?

A

The central nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the role of sensory neurones?

A

To carry information as electrical impulses from receptors to the central nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Muscles and glands are both effectors. How would each of these respond to a nervous impluse?

A

Muscles would contract and glands would secrete hormones.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which part of the nervous system do motor neurones carry electrical impulses to?

A

Effectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

True of false? Reflex arcs don’t involve the conscious parts of the brain. Explain your answer?

A

True. Reflex arcs pass through the spinal cord or unconscious parts of the brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do reflexes reduce the chances of being injured?

A

They allow rapid, automatic responses to harmful stimuli.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the role of a relay neurone in a reflex arc?

A

To connect a sensory neurone to a motor neurone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What term describes the time it takes to respond to a stimulus?

A

Reaction time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Outline an investigation that could be done to measure the effect of caffeine on a person’s reaction time?

A

E.g. hold a ruler between a person’s thumb and forefinger and ask them to catch it as quickly as they can when you drop it. Record the number on the ruler where they caught it, then repeat the test three times and calculate the mean. Next, give the person being tested a caffeinated drink and repeat the experiment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Name the chemical messengers that are secreted directly into the bloodstream by glands?

A

Hormones.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which produce faster and shorter-lasting effects - hormones or nerves?

A

Nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In the liver and muscles, what is excess glucose converted to for storage?

A

Glycogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which hormone causes glucose to move from the blood into liver and muscle cells?

A

Insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does glucagon increase blood glucose levels?

A

It causes glycogen to be converted into glucose and released into the blood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In which type of diabetes does a person become resistant to their own insluin?

A

Type 2 diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is oestrogen produced?

A

In the ovaries.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the main role of testosterone in males?

A

It stimulates sperm production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do oestrogen and progesterone affect the uterus lining?

A

They are involved in its growth (oestrogen) and maintenance (progesterone).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What effect does oestrogen have on the release of LH?

A

Oestrogen stimulates LH production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which hormone do oral contraceptives inhibit the release of?

A

Follicle-stimulating hormone (FSH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which method of contraception is inserted into the uterus to prevent the implantation of a fertilised egg in the uterus wall?

A

Intrautering device (IUD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

some contraceptives work by slowly releasing progesterone. Give two ways that progesterone can reduce fertility?

A

Any two from:

it stops eggs from maturing.
It prevents ovulation (the release of eggs from the overies).
It stimulates the production of a thick mucus which prevents any sperm getting through and reaching the egg.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is a ‘Spermicide’?

A

A chemical that disables or kills sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which two hormones are given to women undergoing IVF to stimulate several eggs to mature?

A

Follicle-stimulating hormone (FSH) and Luteinising Hormone (LH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What stage must embryos have reached before they are transferred from the lab to the mother’s womb during IVF?

A

They must be a tiny ball of cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Give one reason why some people think IVF is unethical?

A

Any one from, e.g.:

It often results in unused embryos that are eventually destroyed, each one representing a potential human life.

The genetic testing of embryos before implantation could lead to the selection of preferred characteristics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which glands release adrenaline?

A

The adrenal glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Adrenaline increases the heart rate. How does this prepare the body for ‘fight or flight’?

A

It increases the supply of oxygen and glucose to cells in the brain and muscles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

True or false? Thyroxine regulates metabolism. Explain your answer?

A

True. It plays an important role in regulating the basal metabolic rate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What type of feedback system controls the level of thyroxine in the blood?

A

A negative feedback system

34
Q

Explain why DNA is described as a ‘double helix’?

A

E.g. It’s made up of two strands coiled together.

35
Q

What name is given to small sections of DNA that code for particular proteins?

A

Genes

36
Q

What is the term used to describe the entire genetic material of an organism?

A

Genome

37
Q

Give one benefit of scientists knowing the complete human genome?

A

Any one from, e.g.

It allows scientists to identify genes in the genome that are linked to different types of disease.

It helps scientists understand inherited disease and develop effective treatments

It means scientists can trace the migration of certain populations of people around the world in the past.

38
Q

Which type of reproduction involves the fusion of gametes?

A

Sexual reproduction

39
Q

What are the gametes in flowering plants?

A

Pollen and egg cells

40
Q

Explain why asexual reproduction doesn’t produce any variation in the offspring?

A

There is only one parent so there is no fusion of gametes and so no mixing of chromosomes. This means that there is no genetic variation between the parent and offspring. The offspring are all genetically identical.

41
Q

Give two differences between sexual and asexual reproduction?

A

Any two from, e.g.:

Sexual reproduction produces variation in the offspring, whereas asexual reproduction produces clones.

Sexual reproduction requires two parents, whereas asexual reproduction only requires one parent.

Sexual reproduction involves meiosis, whereas asexual reproduction only involves mitosis.

Sexual reproduction involves gametes, whereas asexual reproduction doesn’t.

42
Q

Where does meiosis happen in humans?

A

In the reproductive organs (the ovaries in females and testes in males)

43
Q

How does the amount of genetic information in the parent cell change before the first division in meiosis?

A

It doubles

44
Q

Which type of cell devision produces four gametes from a single cell?

A

Meiosis.

45
Q

How many pairs of chromosomes in human body cells control characteristics other than sex?

A

22

46
Q

What chromosome causes male characteristics?

A

Y

47
Q

What is the predicted ratio of male to femail offspring for two parents?

A

50:50

48
Q

Ture of False? All characteristics are controlled by a single gene. Explain your answer?

A

False. Some charateristics (like fur colour in mice and red-green colour blindness in humans) are controlled by one gene, but most characteristics are controlled by several genes interacting.

49
Q

What word is used to describe the different possible versions of a gene?

A

Alleles

50
Q

Explain what the term ‘homozygous’ means

A

That the two alleles for a particular gene are the same.

51
Q

Describe the difference between a person’s genotype and phenotype?

A

The genotype is the mix of alleles that a person has (e.g. Cc or cc), whereas the phenotype is the characteristics they have (e.g. colour blind or not).

52
Q

Describe how you could use a completed Punnet square to find the probability of offspring having a certain phenotype?

A

E.g. find the offspring’s genotypes from the middle squares and, based on what the dominant allele is, work out the possible phenotypes. Then work out the probability by comparing the number of the phenotypes of interest to the total number of possible phenotypes.

53
Q

Explain why both parents of a person with cyctic fibrosis must carry a cystic fibrosis allele?

A

The allele is recessive, so two copies are needed to have the condition. This means one cystic fibrosis allele must have been inherited from each parent in order for the person to have cystic fibrosis.

54
Q

Is polydactyly caused by a recessive or dominany allele?

A

Dominant

55
Q

What is embryo screening?

A

The process of removing a cell from an embryo and looking at its genes.

56
Q

What term is used to describe the differences in the characteristics of individuals in a population?

A

Variation

57
Q

Plant clones kept in different conditions will grow differenty. What type of variation is this most likely to be an example of?

A

Environmental

58
Q

Are most differences in characteristics of individuals in a population caused by genetics, the environment or both?

A

Both.

59
Q

Explain why the presence of a new phenotype can lead to a relatively rapid change in a species if the environment changes?

A

Individuals with the new phenotype maybe more suited to the new environment. These individuals will be more likely to survive and reproduce, so the phenotype will quickly become more common throughout the species by natural selection

60
Q

Explain how natural selection leads to a species evolving?

A

Individuals in a population with the most suitable characteristics for the environment are more likely to survive. The successful individuals that survive are more likely to reproduce and pass on the genes for the beneficial characteristics to their offspring. Over time, individuals with the beneficial characteristics become more common in the population and the species evolves.

61
Q

When is a species defined as ‘extinct’?

A

When no individuals of the species remain alive.

62
Q

Why is Darwin’s theory of evolution by natural selection now an accepted theory?

A

Because there is now so much edidence that supports the theory, such as the fossil record and antibiotic resistance in bacteria. Also scientists now know the mechanisms by which characteristics are passed on to offspring, via their genes.

63
Q

The flowchart below outlines the process of selective breeding. What step is missing?

1) Select animals with desirable characteristics and breed them together.

2) ?????

3) Continue the process for several generations until all the offspring have the desired characteristic.

A

2 = Select the best of the offspring and breed them together.

64
Q

One of the earliest examples of humans using selective breeding is the development of food crops from wild plants. Give another example of an early human use of selective breeding?

A

To get domesticated animals.

65
Q

Give two problems that could be caused by inbreeding?

A

E.g.:

The population could become prone to disease.

Organisms could be more likely to inherit harmful genetic defects.

66
Q

What is used to isolate the useful gene from an organism’s genome in genetic engineering?

A

An enzyme.

67
Q

Give two things that are usually used as vectors in genetic engineering?

A

Bacterial plasmids and viruses.

68
Q

How can genetic engineering be used to help treat diabetes?

A

By genetically modifying bacteria to produce human insulin, which can be given to people with diabetes.

69
Q

Animals can be genetically engineered to produce substances that can be used in medicines. Give one potential benefit to humans of being able to do this, and one reason why some people might object to they type of genetic engineering?

A

E.g. one potential benefit is the opportunity to produce medicines that could treat human diseases. One reason some people might object is that it could cause health problems for the animal/it’s hard to predict how it will affect the animal.

70
Q

What replaces bones as they slowly decay to form fossils?

A

Minerals

71
Q

Describe how a fossil could form from a footprint?

A

The foodprint could press into a soft material which could then harden, leaving an impression of the footprint.

72
Q

Explain why many of the earliest forms of life didn’t form fossils?

A

They were soft-bodied, and soft tissue tends to decay away completely, leaving no trace.

73
Q

How may beological activity have affected our knowledge of how life began?

A

It may have destroyed fossils formed from the earliest organisms.

74
Q

What causes a bacterial cell to become resistant to an antibiotic?

A

A mutation in its DNA

75
Q

Why is the bacteria ‘MRSA’ a problem?

A

Because it is resistant to most known antibiotics.

76
Q

Describe what farmers could do to help reduce the spread of antibiotic-resistant bacteria?

A

Limit the amount of antibiotics they give to their animals.

77
Q

New antibiotics take a long time to develop. What impact does this have on attempts to reduce the spread of antibiotic-resistant bacteria?

A

It makes it harder to reduce the spread, as it makes it difficult for scientists to keep up with the demand for new antibiotics that are needed to fight new antibiotic-resistant strains.

78
Q

What two things about organisms did Carl Linnaeus use to group them together?

A

Their structure and characteristics.

79
Q

Give one reason why new models of classification were proposed after the Linnaean system?

A

Any one from e.g.

Microscopes improved (which allowed scientists to find out more about the internal structures of organisms).

Understanding of biochemical processes taking place inside organisms progressed.

New chemical analysis techniques were developed.

80
Q

Describe what the two parts of an organism’s binomial Latin name refer to?

A

The first part is its genus and the second part is its species.

81
Q

Describe what information evolutionary trees are used to show?

A

E.g. how scientists think different species are related to each other.

B5 Homeostasis and Response/B6 Inheritance, Variation and Evolution (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions