Brainscape's Knowledge GenomeTM

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


See full index

GCSE Biology > B13 - Reproduction - Complete > Flashcards

B13 - Reproduction - Complete Flashcards

You may prefer our related Brainscape-certified flashcards:
GCSE Religious Studies - Edexcel Route A flashcards GCSE Religious Studies - Eduqas Route A flashcards AP® Biology flashcards GCSE Geography - AQA flashcards Biology 101 flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

What are the two types of reproduction?

A

Asexual and sexual

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

What is asexual reproduction?

A

Asexual reproduction has only one parent who replicates their DNA. Their is no fusion or fertilisation and no gametes. The name of this process for cells is mitosis. There is no variation.

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

What is sexual reproduction?

A

Sexual reproduction involves the fusing of two gametes to form a zygote. It involves meiosis. Eggs and pollen are made in plants, and sperm and eggs are formed in animals.

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

Which type of reproduction forms perfect clones?

A

Asexual reproduction

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

How many chromosomes are in a gamete?

A

23

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

How many chromosomes are in a full normal living cell?

A

46

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

What are some examples of things that reproduce asexually?

A

Very small animals, plants, fungi, bacteria

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

What are the 2 types of cell division?

A

Mitosis and meiosis

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

What is meiosis?

A

The division of cells to make specialised sex cells called gametes

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

Where does meiosis take place in humans?

A

The testes and the ovaries, sperm and eggs are made

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

How many new cells are made by meiosis and describe its process?

A

The genetic information is copied so there are four sets of chromosomes which each form chromatids, and then the cells divide rapidly to create 4 new gametes, each with a single set of chromosomes

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

How is variation introduced into meiosis?

A

Each set of chromosomes is mixed randomly from the original ones - meaning that the there are hundreds of different combinations and therefore variation. Each gamete is different

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

How is variation also introduced into the fertilisation process?

A

There are millions of different sperm trying to fertilise the egg - meaning that the chances of each getting their specific alleles to the egg are incredibly small - and only one will succeed.

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

What happens after fertilisation?

A

The two gametes fuse to make a zygote, which has the full amount of chromosomes needed to make a new human, and then it starts dividing rapidly in order to form more new cells and start forming a new baby. As the embryo develops, the cells start to differentiate

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

Which type of reproduction is faster and more efficient?

A

Asexual

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

Due to the complete identical nature of its offspring, what can happen if there is a change in environment for an asexually reproducing individual?

A

It and all its offspring can die if the change is severe enough

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

What is natural selection?

A

The defining of offspring so that only the strongest can survive by means of changes in the environment that cause death. The fact that some survive and others don’t is due to variation in the offspring

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

How do fungi reproduce?

A

Fungi reproduce asexually in good conditions (using spores), but when it is dry or there are other problems, they have the ability to reproduce sexually

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

How can plants reproduce?

A

Sexually, with pollen and egg, and asexually using long ‘runner’ stems that can grow tiny new plants on the end, and the division of bulbs

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

How do malarial parasites reproduce?

A

Malarial parasites reproduce sexually and asexually throughout their life spans: when they burst into the human body for a short period the join others to make full sets of DNA, and then they start rapidly reproducing. They often show a lot of variation

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

What is DNA?

A

A long polymer that stands for deoxyribonucleic acid. It contains our genes in the form of different base combinations

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

What structure does DNA form?

A

A double helix structure

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

A chromosome contains thousands of _____ joined together

A

Genes

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

What is the genome of an organism?

A

The entire genetic material of that organism

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

Why was the Human Genome Project so important?

A

It means that we can now understand genetic disorders such as sickle cell disease and cystic fibrosis, as well as that we can understand how some genes are linked to the increased likelihood of getting specific diseases such as type 2 diabetes. Additionally, helps us understand human evolution and history and lets us see where we came from and when

26
Q

What is a gene?

A

A small strand of DNA on a chromosome. Each gene codes for a particular sequence of amino acids, to make a specific protein

27
Q

Where is DNA found in a cell and what exactly does it control?

A

In the nucleus, it controls protein synthesis

28
Q

What letters represent the bases in DNA?

A

A, C, G and T

29
Q

What is a nucleotide?

A

The combination of a sugar, phosphate, and a base is called a nucleotide. DNA is a polymer made up of many repeating units of nucleotides

30
Q

How many bases code for each amino acid?

A

3

31
Q

How does the process of protein synthesis take place?.

A

First, a template of the protein chain to be synthesised is made inside the DNA. Then, the template leaves the nucleus and binds to the surface of a ribosome. The carrier molecules of amino acids inside the cytoplasm then assemble into the series needed for the protein until the series is complete. The carrier molecules then detach and the process is complete.

32
Q

What could a mutation cause in protein synthesis?

A

A problem whereby the amino acids are assembled incorrectly and therefore the whole protein being produced may not work

33
Q

What do scientists think the non-coding part of our DNA does?

A

They believe it allows certain parts of our DNA to be turned on or off - so that genes can code multiple proteins each. They believe that changes in tis non-coding part of our DNA could change which genes are expressed - therefore effecting our phenotype

34
Q

What are mutations and what do they do?

A

Mutations are changes in the sequences of our DNA bases that are often a result of bad copying of our DNA by our cells. They are often insignificant and do not change the protein formed enough to make a significant difference and effect its function, however sometimes they can cause significantly bad changes

35
Q

What are the easiest characteristics to monitor and predict?

A

Ones that are caused by a single gene - rather than made up of multiple

36
Q

What is a genetic cross?

A

A cross that maps the father’s and the mother’s genes against each other in order to create for separate possibilities - and therefore making it easy to predict the % chance of certain genes being expressed

37
Q

What is a homozygote?

A

A homozygote is a specimen with two identical alleles for a characteristic, e.g. BB or bb

38
Q

What is a heterozygote?

A

A heterozygote is a specimen with two different alleles for a specific characteristic, e.g. Bb

39
Q

What is a genotype?

A

A genotype if the genetic make up of an individual regarding a specific characteristic, for example Bb, IT IS NOT THE CHARACTERISTIC’S EXPRESSION

40
Q

What is a phenotype?

A

A phenotype is the expression of a gene regarding a specific characteristic, such as black or brown fur in a mouse

41
Q

What does a capital letter mean in a Punnett Square?

A

It means that that gene is dominant - small one means that it is recessive

42
Q

What does dominant or recessive genes mean?

A

It means that if the gene is present in the genetic makeup, it will be expressed. A recessive allele needs two of itself to be expressed

43
Q

What are two ways of demonstrating the inheritance of genes in a diagram?

A

Family trees and Punnet squares

44
Q

Why is it that despite the probability of having each gender being 50:50, the population is not split exactly that way?

A

As it is just probability, which does not demonstrate the actual results, just the likelihood of each result. The event itself is random and cannot be predicted precisely

45
Q

How many chromosomes do humans normally have and how many determine someone’s sex?

A

Humans normally have 23 pairs of chromosomes and 1 determines the person’s sex

46
Q

What is polydactyly?

A

A genetic malfunction whereby someone grows an extra toe or finger.

47
Q

What is cystic fibrosis?

A

A genetic disorder whereby cell membranes disallow certain substances from crossing from one side to the other

48
Q

What are the effects of cystic fibrosis?

A

Mucus in many areas of the body becomes very thick and sticky, lungs can be clogged by thick mucus, the pancreas cannot make and secrete enzymes properly, many people with cystic fibrosis are infertile

49
Q

What is someone who carries a gene but does not exhibit its symptoms called?

A

A carrier

50
Q

What could be a cure in the future for genetic disorders such as cystic fibrosis?

A

Genetic engineering

51
Q

What sort of issue has to be considered within genetic screening for problems?

A

Ethical

52
Q

What are the two main methods of screening once pregnancy is underway?

A

Amniocentesis and Chorionic Villus

53
Q

When is amniocentesis carried out?

A

15 - 16 weeks of pregnancy

54
Q

When is chorionic villus carried out?

A

10 -12 weeks of pregnancy

55
Q

Describe the process of amniocentesis

A

Amniocentesis is carried out at around 15 - 16 weeks of pregnancy. It involves taking some of the amniotic fluid from the developing fetus. This fluid contains fatal cels, which can then be used for genetic screening

56
Q

Describe the process of chorionic villus

A

Chorionic villus is carried out at around 10 - 12 weeks of pregnancy by taking a small tissue sample from the placenta for screening

57
Q

What main problem can be caused as a result of chorionic villus and amniocentesis?

A

Miscarriage

58
Q

What choice do the barents receive if their fetes has a genetic problem that showed up in screening?

A

They can keep the baby or have an abortion / choose not to have it implanted (if it is an IVF baby)

59
Q

What problems can be caused due genetic screening in embryos?

A

Miscarriages, false positive or negative results, puts parents in the horrible position of having to choose whether or not they want to terminate a pregnancy

60
Q

What factors can effect who gets embryonic screening or not?

A

Whether the family has a history of genetic problems or disorders, and whether they can afford it, as currently embryonic screening is very expensive

61
Q

What do doctors hope to do in the future?

A

Have techniques and cures that could cure the problems before the baby was born, and therefore resulting in them being able to be born without the genetic problem

GCSE Biology (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions