Reproduction Flashcards
1
Q
What are the human gametes?
A
Egg cell
Sperm cell
2
Q
What are the plant gametes?
A
Egg
Pollen
3
Q
Egg cell + sperm cell —> ?
A
Foetus
4
Q
Pollen + egg —> ?
A
Seed
5
Q
What is a gamete?
A
A sex cell
6
Q
How many parents does sexual reproduction involve?
A
2 parents
7
Q
What is used to create gametes?
A
Meiosis
8
Q
How much DNA comes from the mum?
A
50%
9
Q
How much DNA comes from the dad?
A
50%
10
Q
What does a mix of DNA lead to?
A
Inherited variation
11
Q
Sperm and egg cells are what type of cells?
A
Haploid
They only contain half the genetic material
12
Q
What is a haploid cell?
A
Has half the number of chromosomes of a normal body cell
23 chromosomes
13
Q
How many chromosomes does a sperm and egg cell have?
A
23 each
14
Q
How many chromosomes does a human cell have?
A
46
15
Q
What type of cell is a human cell?
A
Diploid cell
16
Q
What is a diploid cell?
A
A cell with the full number of chromosomes
Humans: 46
17
Q
How many parents does asexual reproduction involve?
A
1 parent
18
Q
Does sexual reproduction involve gametes?
A
Yes
19
Q
Does asexual reproduction involve gametes?
A
No
—> no mixing of genetic material (no genetic variation)
20
Q
What do the offspring from asexual reproduction look like?
A
Identical clones of the parent
21
Q
What is a clone?
A
An organism that is genetically identical to its parent
22
Q
How do eukaryotic organisms clone themselves?
A
By mitosis
23
Q
How do prokaryotic organisms clone themselves?
A
By binary fission
24
Q
How can strawberries reproduce?
A
Both sexually and asexually
25
How do strawberries reproduce sexually?
Using seeds
26
How do strawberries reproduce asexually?
Using runners
27
What is a hybrid?
An organisms made by breeding two different species
28
What is the result of a hybrid organism?
It is infertile
29
What are the different methods plants use to reproduce asexually?
Tubers
Runners
Spores
Bulbs
Cuttings
30
How do tubers work in asexual reproduction for plants?
Tubers contain genetic information
The tip of the tuber grows upwards and forms a new plant
31
Where are tubers produced?
Potatoes
32
How do runners work in asexual reproduction for plants?
Strawberry runners grow outwards from the plant
Where the runners touch the soil they put down roots and eventually they will become new strawberry plants
33
Where are runners produced?
Strawberries
34
How do spores work in asexual reproduction for plants?
Spores contain both the male and female reproductive organs
Plants with spores can reproduce on their own
35
Where are spores produced?
Some plants
36
How do bulbs work in asexual reproduction for plants?
The bulb splits and forms new bulbs called bulblets
37
Where are bulbs produced?
Some plants
38
How do cuttings work in asexual reproduction for plants?
A gardener takes a cutting from a leaf or shoot of an existing plant
This cutting can be grown to make a new plant
39
What can plant reproduction be artificially created from?
Cuttings
40
What is the function of the nucleus of an egg cell
Contains 50% DNA (genetic information) from the mother
41
What is the function of the jelly coat of an egg cell?
To harden after 1 sperm enters to stop others getting in
42
What is the function of the cytoplasm of an egg cell?
Food store which contains nutrients to support the developing embryo
43
Where does fertilisation happen?
In the oviduct
44
Where does ovulation occur?
In the ovaries
45
Where does implantation occur?
On the uterus lining
46
Where does ejaculation occur?
In the vagina
47
What is the function of the cervix?
Ring of muscle which keeps the baby in place during pregnancy
48
What is the function of the ovaries?
Contains hundreds of undeveloped eggs
Every month an egg cell matures and is released
49
What is the function of the oviduct?
Carries egg cells from the ovaries to the uterus
Fertilisation occurs here
50
What is the function of the uterus?
Where the baby develops during pregnancy
51
What is the function of the uterus lining?
A blood rich layer of tissue in which an embryo implants
This tissue is lost each month during menstruation
52
What is the function of the vagina?
A muscular tube that leads from the cervix to outside the body
Penis enters here and deposits sperm
53
What is ejaculation?
The ejection of semen through the penis
54
What is fertilisation?
The fusion of gametes to form a zygote
55
What is implantation?
When an embryo attaches to the uterus lining
56
What is ovulation?
The release of a mature egg cell from the ovary
Occurs once every 28 days
57
Adaptations of the sperm cell
Streamlined shape
Has a flagellum (tail)
Enzymes in the head (acrosome)
Many mitochondria
58
Adaptions of the egg cell
Cytoplasm containing a store of energy
Jelly like coating that changes after fertilisation
59
What is the function of the streamlined shape of a sperm cell?
For efficient swimming to the egg
60
What is the function of the nucleus of a sperm cell?
Contains 50% of DNA (genetic information) from the father
61
What is the function of the tail/flagellum of a sperm cell?
Allows the cell to swim towards the egg to fertilise it
62
What is the function of the enzymes in the head of a sperm cell?
To digest the jelly coat and cell membrane of an egg cell
63
What is the function of the many mitochondria in the mid piece?
To provide energy from respiration so that the flagellum can move back and forth for locomotion (so it can move)
64
What is the function of the penis?
Allows urine and semen to pass out of the man’s body
65
What is the function of the prostate gland?
Produces fluid called semen that provide sperm cells with nutrients
66
What is the function of the scrotum?
A sac of skin supporting the testes outside the body to ensure sperm are kept at a temperature slightly lower than body temperature
67
What is the function of the sperm duct?
Carries sperm cells from the testes to be mixed with fluids produced by the glands before being passed into the urethra (for ejaculation)
68
What is the sperm duct also called?
Vas deferens
69
What is the function of the testes?
Contained in the scrotum and produces sperm cells and the male sex hormone testosterone
70
What is the function of the urethra?
A tube that carries urine and semen out of the body which has a ring of muscle to keep these fluids separate
71
What is the function of the fore skin?
The outer layer of skin around the tip of the penis to protect it
72
What do the ovaries contain?
Immature egg cells
73
What happens to the egg cells after puberty?
They begun to develop and mature
74
How often is an egg released from an ovary?
Around every 28 days
75
When do a women’s ovaries stop releasing eggs?
Between 45-55 years old
76
What is menopause?
When a women stops releasing eggs and having periods so she can’t get pregnant naturally anymore
77
What happens when the egg is released from the ovary?
Hairs inside the oviduct called cilia help waft the egg along towards the uterus
78
What are the hairs in the oviduct called?
Cilia
79
What happens if the egg is fertilised in the oviduct?
It passes into the uterus and implants in the uterus lining
80
Stages of human reproduction in order
Gamete production
Ovulation
Sexual intercourse
Ejaculation
Sperm swims to the egg
Fertilisation
Zygote formed
Cell division
Embryo formed
Implantation
Foetus formed
Labour
Birth
81
What is the menstrual cycle?
A monthly process in females that prepares the body for pregnancy and lasts around 28 days
82
What is the menstrual cycle controlled by?
Hormones
83
What can the changes in hormone levels during the menstrual cycle make women experience?
Physical and emotional change
84
What are examples of physical and emotional changes for women during the menstrual cycle?
Feeling bloated
Having tender breasts
Having oily hair and skin
Experiencing mood swings
Cramps in lower abdomen
Headaches
Tiredness
85
Which hormones does the pituitary gland secrete?
ADH
FSH
LH
86
Which hormone does the thyroid gland secrete?
Thyroxine
87
Which hormone does the adrenal gland secrete?
Adrenaline
88
Which hormones does the pancreas secrete?
Insulin
Glucagon
89
Which hormones do the ovaries secrete?
Oestrogen
Progesterone
90
Which hormone do the testes secrete?
Testosterone
91
What is the function of oestrogen?
To build up the uterus lining
92
What is the function of progesterone?
To maintain the uterus lining
93
What is the function of LH?
Causes the release of an egg
94
What is the function of FSH?
To begin the menstrual cycle
95
What does FSH stand for?
Follicle stimulating hormone
96
What does LH stand for?
Luteinising hormone
97
What is the first stage of the menstrual cycle?
Menstruation (period starts)
Uterus lining breaks down
—> happens if no fertilisation occurred in the last cycle
98
What is the second stage of the menstrual cycle?
FSH is released
Stimulates an egg to mature in the ovary
Triggers the ovaries to produce oestrogen
99
What is the third stage of the menstrual cycle?
Oestrogen levels rise:
Causes the lining of the uterus to begin to build up again (repairs and thickens)
Stops more FSH secreting (so only one egg matures)
Stimulates LH production
An egg cell starts to mature in the ovary
100
What is the fourth stage of the menstrual cycle?
LH is produced - causes the follicle to change to stop oestrogen production
An egg cell is released from the ovary (ovulation)
101
What is the fifth stage of the menstrual cycle?
Progesterone is released to maintain/thicken the uterus lining in case of fertilisation
Stops release of FSH and LH
102
What is the sixth stage of the menstrual cycle if no fertilisation occurred?
Progesterone levels fall
Uterus lining breaks down
New cycle begins
103
Order of the menstrual cycle
Menstruation (period starts)
FSH released
Oestrogen levels rise
LH peaks —> ovulation
Progesterone released
Uterus lining breaks down (if no fertilisation occurs)
104
What is fertilisation?
The fusion of a male and female gamete forming a zygote
105
What happens when the sperm meets the egg?
Sperm approaches the egg
Enzymes digest the jelly coat and membrane
Sperm nucleus enters the egg
Membrane becomes impenetrable to anymore sperm
106
How many chromosomes does a zygote contain?
46
107
What is implantation?
Happens about 5 days after fertilisation, the embryo attaches to the uterus lining
108
How does a zygote turn into a foetus (steps)?
Gametes fuse together to become a zygote
Zygote undergoes cell division to form an embryo
More growth and cell division forms a foetus
109
What happens in cell division?
One cell divides into two identical cells
—> which then divide into four identical cells
Eventually a ball of cells if formed, this is called any embryo
110
111
What is gestation?
The period of time between fertilisation and birth when a baby develops in the uterus of a woman
112
How long does gestation last in humans?
40 weeks (9 months)
113
What is the placenta?
An organ for exchange of substances between the mother’s blood and the baby’s blood (via diffusion)
114
Does the blood between the baby and the mother mix?
No just gets close
115
What should the mother avoid when pregnant?
Drinking
Smoking
Drugs
Infections
116
What are the adaptation of the placenta for exchange of materials?
Large surface area
Short diffusion distance
117
Which substances travel from mum to baby?
Glucose
Amino acids
Fatty acids
Water
Oxygen
Mineral ions
Vitamins
118
Which substances travel from baby to mum?
Carbon dioxide
Urea
119
Which week marks the end of the first trimester?
Week 12
120
How does the baby get its nutrients?
From the placenta
121
At what week can the baby survive outside the uterus?
Week 24
122
Where does the foetus develop?
Inside the amniotic sac
123
What is another name for the amniotic sac?
Amnion
124
What is the amniotic sac filled with?
Fluid for protection
125
What does the amniotic fluid act as?
A shock absorber and cushioning from any bumps
126
What are the stages of pregnancy?
Fertilisation
Zygote
Embryo
Foetus
Implantation
Placenta function
Gestation
Birth
127
How does labour start?
When muscles in the uterus wall start to contract and dilate the cervix
128
How long can contractions last for?
Several hours especially for first-time mothers
129
What does the mother’s water breaking mean?
When the amniotic sac bursts and amniotic fluid flows out of the vagina
130
What happens during the second stage of labour?
The cervix is fully dilated (10cm)
The mother pushes with each contraction to help the baby come out
The baby is born (head first)
131
What does ‘crowning’ mean?
When the top of the baby’s head is first seen
132
What happens during the third stage of labour?
(About 15-30 mins after the baby is born)
The uterus contracts and the placenta detaches from the uterus wall
133
What does afterbirth mean?
When the placenta and umbilical cord flow out of the vagina
134
What kind of characteristics are the sex organs?
Primary sexual characteristics
135
Children are …
Sexually immature
136
What does sexually immature mean?
An organism is not yet capable of reproducing
137
What happens when teenagers become sexually mature?
They gain secondary sexual characteristics
138
What is adolescence?
The process of becoming an adult and involves many physical and emotional changes
139
What is puberty?
Period in which adolescents start to develop secondary sexual characteristics
140
How is puberty started?
The body produces sex hormones
141
What happens when the body starts producing sex hormones?
Body starts producing sperm or maturing and releasing egg cells
Developing to allow reproduction
142
What are some puberty changes in males?
Growth and development of male sexual organs
Chest and facial hair grows
Voice breaks
Shoulders widen
143
What are some puberty changes in both males and females?
Mood swings
Acne
Growth spurt
Armpit and pubic hair grows
Stronger body smell
144
What are some puberty changes in females?
Growth and development of female sexual organs
Eggs released each month (menstrual cycle starts)
Breasts develop
145
Which two hormones are both secreted in males and females?
FSH
LH
146
What is the function of FSH in males?
Stimulates sperm production
147
What is the function of LH in males?
Stimulates testosterone production
148
What does testosterone result in for males?
Secondary sexual characteristics
149
What is the function of FSH in females?
Stimulates egg development and oestrogen production
150
What is the function of LH in females?
Stimulates ovulation
151
What does oestrogen result in for females?
Secondary sexual characteristics
