Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology by Thaidz > Reproduction and Inheritance > Flashcards

Reproduction and Inheritance Flashcards

1
Q

what are chromosomes?

A

long lengths of DNA coiled up

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

what are genes?

what do they do?

A

sections of DNA
chemical ‘instructions’ for making an organism
codes how to make particular proteins
proteins determine inherited characteristics
two copies, one from each parent

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

where are chromosomes found ?

A

In the nucleus

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

Human cells are which? haploid/diploid

A

diploid

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

what is a diploid cell?

A

has two sets of chromosomes (in pairs)

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

what is an allele ?

A

different versions of the same gene
(eye colour) (hair colour)
can be recessive or dominant

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

what is a dominant allele?

A 
allele characteristic develops only if allele is present on one or both chromosomes in a pair 
Capital letter (C)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a recessive allele?

A 
allele characteristic only develops if allele is present on both chromosomes in a pair 
small letter (c)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is homozygous ?

A

identical alleles in a gene

CC or cc

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

what is hetrozygous ?

A

two different alleles in a gene

Cc

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

what is the Genotype ?

A

the alleles you have

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

what is the Phenotype ?

A

the characteristics the alleles produce

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

what is Mono hybrid cross ?

A

breeding two organisms to look at one characteristic

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

what is the phenotypic ratio ?

A

ratio of different ratios in punnet square

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

what is a condominant allele?

example?

A

neither allele is recessive so characteristics shown from both alleles
e.g. not blood group A or B, but AB

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

what is DNA?

how is it held together?

A

strands coiled together in a double helix
strands held together by chemical bases A C G T
bases are paired, always A-T and C-G, called complementary base-paring
DNA is a nucleic acid

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

what are the Bases names for A T C G?

A

adenine
cytosine
guanine
thymine

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

what is asexual reproduction ?

A

involves only one parent. The offspring have identical genes to the parent - so there’s no variation between parent and offspring

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

Asexual reproduction is mitosis/meiosis

A

mitosis

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

what is mitosis ?

where does it take place?

A

cell reproduces itself by splitting to form 2 cells with identical sets of chromosomes (identical genetic info)
takes place everywhere

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

what are the uses for mitosis ?

A

asexual reproduction
growth and repair
cloning

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

The two different ways plants reproduce asexually

A

Growing new plants from its stem

Cloning

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

describe how strawberry plants asexually reproduce

A

Parent strawberry plant send out runners (fast growing stems) above ground
Runners take root at various points
New plants are clones so no genetic variation

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

what is sexual reproduction ?

A

fusion of male and female gametes to produce genetically different offspring, because there are two parents, offspring contain mixture of parent’s genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is the Male (human) gamete
sperm cell
26
what is the Female (human) gamete
egg cell
27
human gametes are diploid/haploid ... | how many chromosomes does each have?
haploid meaning they have half as normal cell | 23 chromosomes each
28
define human fertilisation
fusion of male and female gamete to form a zygote | zygote has full set of chromosomes (diploid)
29
human sexual reproduction - what is the process after zygote formed to embryo ?
zygote undergoes cell division (by mitosis) and develops into an embryo
30
what is meiosis ? | where does it happen?
cell division, produces 4 haploid cells whose chromosomes are not identical only happens in reproductive organs for humans
31
what is the stamen ?
plant male reproductive part | consists of anther and filament
32
what is the anther ?
contains pollen grains which produce male gametes
33
what is the filament ?
stalk that supports the anther
34
what is the carpel ?
female plant reproductive part | consists of ovary, style and stigma
35
what is the stigma ?
end bit that pollen grains attach to
36
what is the style ?
rod-like section that supports stigma
37
what is the ovary ?
contains female gametes inside ovules
38
what is pollination ?
transfer of pollen from anther to stigma, so that male gametes can fertilise female gametes in sexual reproduction
39
what is cross - pollination ?
type of sexual reproduction where pollen is transferred from one plant to the stigma of another cross-pollinating plants rely on insects/wind
40
how are plants adapted for insect pollination ?
brightly colour petals to attract insects scented flowers and nectarines sticky pollen grains which stick to insects stigma also sticky so pollen sticks on it
41
what are nectarines ?
glands in plant which secrete nectar
42
how are plants adapted for wind pollination ?
small dull petals - no need to attract no nectarines / scents needed lots of small / light pollen grains long filaments that hang anthers outside to release pollen large feathery stigma outside to catch pollen
43
how does plant fertilisation happen?
pollen lands on stigma - pollen tube grows out of pollen into ovule - nucleus from male gamete moves down to join female gamete - fertilisation occurs to form zygote - zygote uses to mitosis to form embryo - each fertilised female gamete forms seed - ovary develops into fruit around seed
44
define fertilisation
fusion on gametes to form zygote
45
what are the conditions needed for germination ? | why are these needed?
water - activate enzymes to break down food reserves oxygen - for respiration, provides energy for growth suitable temp - optimum temp for enzymes (depends on type of seed)
46
how does a germinating seed get energy ? | what is the energy needed for?
seed contains embryo and food reserves wrapped in hard seed coat uses glucose for respiration for energy to grow once leaves develop, it can photosynthesise
47
explain how you can artificially clone a plant | why is this effective?
can take cuttings from good plants and plant them to produce genetically identical clones these plants can be produced fast and cheap
48
what is the urethra ?
tube which carries sperm through penis during ejaculation. Also urine passes through here
49
what is the erectile tissue ?
swells when filled with blood to make penis erect
50
what is the testis (plural testes)?
where sperm is made
51
what is the glands ?
produce liquid that's added to sperm to make semen
52
what is the sperm duct ?
muscular tube that carries sperm from testis towards urethra
53
what is the scrotal sac ?
hangs behind penis and contains testes
54
how often is an ovum (egg) produced?
every 28 days
55
what if an egg doesn't get fertilised?
ovum breaks up, and pass out of vagina
56
what if an egg does get fertilised?
ovum starts to divide, new cells travel down Fallopian tube to uterus and attach to uterus lining, develops into embryo
57
what does ovum mean?
egg
58
what is the Fallopian tube (oviduct)?
muscular tube that carries ovum from ovary to uterus
59
what is the ovary ?
organ that produces eggs (ova) and sex hormones
60
what is the uterus (womb)?
organ where embryo grows
61
what is the vagina ?
where sperm is deposited
62
what is the cervix ?
neck of the uterus
63
what is the uterus lining ?
has good blood supply for implantation of embryo
64
what are the female secondary characteristics and hormone ?
``` oestrogen causes : extra body hair hips widen development of breasts ovum release and start of periods ```
65
what are the male secondary characteristics and hormone ?
``` testosterone causes : extra body / facial hair muscles develop penis and testicles enlarge sperm production deepening of the voice ```
66
what is the stage 1 of menstrual cycle ?
bleeding starts | uterus lining breaks down for about 4 days
67
what is the stage 2 of menstrual cycle ?
uterus lining builds up again from day 4 to 14, into think spongy layer of blood vessels, ready to receive fertilised egg
68
what is the stage 3 of menstrual cycle ?
an ovum develops and is released from the ovary at day 14
69
what is the stage 4 of menstrual cycle ?
walls is then maintained for about 14 days until day 28. | If no fertilised egg lands, uterus lining breaks down
70
what is oestrogen for? (menstrual cycle) | when is it produced?
causes uterus lining to thicken and grow | stimulates (production of LH to) release of an ovum at day 14
71
what is progesterone for? (menstrual cycle) | when is it produced?
maintains uterus lining when progesterone levels fall, uterus lining breaks down if becomes pregnant, levels stay high
72
what is the function of the placenta ?
provides developing baby with nutrients / oxygen | takes away waste
73
what is the function of the amniotic sac?
full of amniotic fluid which surround embryo to protect it
74
what is the 23rd chromosome labelled ?
XX or XY
75
what causes male characteristics ?
The Y chromosome causes males (so XY)
76
what causes female characteristics ?
XX chromosomes
77
what causes genetic variation ?
Sexual reproduction and mutation in genes
78
List some variation factors which aren't affect by the environment
eye colour hair colour inherited disorders (cystic fibrosis) blood group
79
How can the environment affect height / weight ?
the diet - so poor diet leads to stunting growth
80
List the variation factors of plants
sunlight / moisture level / temp / mineral content of soil | The environment greatly affects plants
81
State the theory of evolution
Life began as simple organisms from which more complex organisms evolved
82
what is a mutation ? | describe how they work
a random change in DNA changes sequence of DNA bases, changing the production of protein, which could lead to new characteristics, increasing variation
83
Explain how a mutation can happen spontaneously
this happens when a chromosome doesn't quite copy itself properly
84
How can you increase chances of a spontaneous mutation ?
ionising radiation - X-rays / gamma rays ... | chemicals called mutagens - like in tobacco
85
Give the answer for a 5 mark what is natural selection question
genetic mutations in an organism lead to variation variation can lead to specific organisms surviving organisms go onto to reproduce and pas on their genes to their offspring happens over several generations
86
how can mutations be harmful ?
if occurs in reproductive cell, offspring might develop abnormally or die if occurs in body cell, mutant cell may multiply and invade parts of body (cancer)
87
explain how antibiotic-resistant bacteria come about and how they are a problem
random mutations in DNA causes them to resist antibiotics, so live longer and reproduces, passing on resistant gene problem because they are much harder to get rid of

Biology by Thaidz (10 decks)

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