Section 7 - Reproduction and Inheritance 2 Flashcards Preview

Edexcel GCSE Biology > Section 7 - Reproduction and Inheritance 2 > Flashcards

Flashcards in Section 7 - Reproduction and Inheritance 2 Deck (47)
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1
Q

What are sperm, where are they made and when (3)

A
  • Male gametes
  • Made in the testes
  • All the time after puberty
2
Q

Sperm mix with a liquid to form …. , which is ejaculated from the …….. to the ………. of the female during sexual intercourse

A

semen

penis

vagina

3
Q
A
4
Q

What is 1 and what is its purpose (2)

A
  • Bladder
  • Stores urine
5
Q

What is 2 and what is its purpose (2)

A
  • Glands
  • Produce the liquid that’s added to sperm to make semen
6
Q

What is 3 and what is its purpose (3)

A
  • Sperm duct (vas deferens)
  • Muscular tube
  • Carries sperm from testis towards the urethra
7
Q

What is 4 and what is its purpose (3)

A
  • Urethra
  • Tube which carries sperm through the penis during ejaculation
  • Urine also passes through the urethra before leaving the body
8
Q

What is 6 and what is its purpose (2)

A
  • Testis
  • Where sperm is made
9
Q

What is 8 and what is its purpose (2)

A
  • Scrotal sac/scrotum
  • Hangs behind the penis and contains the testis
10
Q

What is erectile tissue (1)

A
  • Swells when filled with blood, making the penis erect
11
Q
A
12
Q

What are female gametes (1)

A
  • Ova
13
Q

How and when is an ovum produced (2)

A
  • Every 28 days
  • From one of the two ovaries
14
Q

What happens once an ovum is produced (2)

A
  • Passes into the fallopian tube
  • Might meet sperm that have entered the vagina during sex
15
Q

What happens if an ovum isn’t fertilised by sperm (2)

A
  • Ovum will break up
  • And pass out of the vagina
16
Q

What happens if the ovum is fertilised (2)

A
  • Ovum starts to divide
  • New cells will travel down the Fallopian tube to the uterus
  • Attaches tp endometrium (uterus lining)
  • Fertilised ovum develops into an embryo
17
Q
A
18
Q

What is 1 and what is its purpose (2)

A
  • Ovaduct (Fallopian tube)
  • Muscular tube that carries the ovum from the ovary to the uterus
19
Q

What is 2 and what is its purpose (2)

A
  • Ovary
  • The organ that produces ova and sex hormones
20
Q

What is 3 and what is its purpose (2)

A
  • Uterus (womb)
  • The organ where an embryo grows
21
Q

What is 4 and what is its purpose (2)

A
  • Cervix
  • Neck of the uterus
22
Q

What is 5 and what is its purpose (2)

A
  • Bladder
  • Stores urine
23
Q

What is 6 and what is its purpose (2)

A
  • Urethra
  • Organ where an embryo grows
24
Q

What is 7 and what is its purpose (2)

A
  • Vagina
  • Where sperm are deposited
25
Q

What are the sex hormones in men and women (2)

A

Men - testosterone

Women - oestrogen

26
Q

What 4 things does oestrogen in women cause (4)

A
  • Extra hair on underarms and pubic area
  • Hips to widen
  • Development of breasts
  • Ovum release and start of periods
27
Q

What 5 things does testosterone in men cause (5)

A
  • Extra hair on face and body
  • Muscles to develop
  • Penis and testicles to enlarge
  • Sperm production
  • Deepening of voice
28
Q

What are stages 1 and 2 of the menstrual cycle (4)

A
  • S1 : Day 1 is when bleeding starts
  • Uterus lining breaks down for about four days
  • S2 : The uterus lining builds up again
  • From day 4 to 14, devleops into a thick spongy layer of blood vessels ready to recieve a fertilised ovum
29
Q

What are stages 3 and 4 of the menstrual cycle (4)

A
  • S3 : An ovum develops and is released
  • Released from the ovary at day 14
  • S4 : The wall is maintained for about 14 days until day 28
  • If no fertilised ovum has landed on the uterus wall by day 28, spongy lining starts to break down and cycle starts again
30
Q
A
31
Q

Where are oestrogen and progesterone produced (1)

A
  • Ovaries
32
Q

What does oestrogen do (2)

A
  • Causes the lining of the uterus to thicken and grow
  • Oestrogen stimulates the production of LH, which stimulates the release of an ovum at day 14
33
Q

What does progesterone do (2)

A
  • Maintains the lining of the uterus
  • When the level of progesterone falls, the lining breaks down
34
Q

How do progesterone levels change if the women is pregnant (3)

A
  • Progesterone levels stay high
  • Instead of falling
  • To maintain the lining of the uterus during pregnancy
35
Q
A
36
Q

What is the term for when a baby starts to look human in the later stages of pregnancy (1)

A
  • Fetus
37
Q

When does the placenta develop and what does it do (2)

A
  • Once the embryo has imolanted in the uterus
  • Lets the blood of the embryo and mother come very close to allow the exchange of food, oxygen and waste
38
Q

Where is amniotic fluid found and what does it do (2)

A
  • Found in the amnion membrane, which surronds the embryo
  • Protects the embryo against bumps and knocks
39
Q

What 3 factors aren’t affected by enviornment (3)

A
  • Eye and hair colour
  • Inherited disorders
  • Blood group
40
Q

What is the theory of evolution (1)

A
  • Life began as simple organisms from which more complex organisms evolved
41
Q

Explain the process of natural selection (6)

A
  • Resources living things need to survive are limited
  • Individuals compete for resources to survive, only some surviving
  • Some varieties of a particular species will have a better chance of survival
  • Those varieties will then have an increased chance of breeding and passing on genes
  • A greater proportion of individuals in the next generation have beter alleles, better characteristics for survival
  • Over many generations, species become better able to survive. ‘Best’ features are naturally selected and species adapt
42
Q

What are mutations (1)

A
  • rare, random changes to the genetic code
43
Q

Give two ways mutations can be harmful (2)

A
  • If a mutation occurs in reproductive cells, offspring might abnormally develop, or die
  • If a muation occurs in body cells, mutant cells may multiply in an uncontrolled way, causing cancer
44
Q

Give two ways the chance of mutation is increased (2)

A
  • Ionising radiation, e.g X rays
  • Chemicals called mutagens, e.g chemicals in tobacco
45
Q
A
46
Q

How can mutations be beneficial (3)

A
  • Give an organism a survival advantage
  • Organism can live on in conditions where the others die
  • Natural selection
47
Q

How can bacteria evolve and become antibiotic-resistant (5)

A
  • Bacteria develop random mutation in DNA
  • Sometimes, means a bacterium is less affected by a particular anti biotic
  • Therefore lives for longer and reproduces many more times
  • Leads to natural selection
  • Problem for those who are affected bu the bacteria, as it is no longer easy to get rid of