Unit 16 - Reproduction Flashcards
1
Q
Asexual reproduction
A
The process resulting in the production of genetically identical offspring from one parent
2
Q
Examples of organisms that can reproduce asexually
A
- Starfish
- Yeast
- Plants such as ferns
3
Q
Advantages of asexual reproduction
A
- Only one parent is needed - saves time and energy
- Organisms reproduce very quickly - example bacteria can divide every 20 minutes
- Helps farming due to easy reproduction
4
Q
Disadvantages of asexual reproduction
A
- All individuals have same characteristics
- Vulnerable to environmental changes
- One infection can spread to all
5
Q
Sexual reproduction
A
The process involving the fusion of the nuclei of two specialized sex cells to form offspring
6
Q
Male gamete
A
Sperm cell
7
Q
Female gamete
A
Ovum/egg cell
8
Q
Haploid
A
- The nucleus of a gamete
- Has 23 chromosomes
9
Q
Diploid
A
- Nucleus of a zygote
- Has 46 chromosomes (23 pairs)
10
Q
Advantages of sexual reproduction
A
- Introduces variation to the population
- More resistance to environmental changes and diseases
- Farmers making crops can choose the best characteristics from different strains to produce new plants
11
Q
Disadvantages of sexual production
A
- A lot of time and energy is spent finding a mate and reproducing
- Much slower than asexual reproduction - months or years
12
Q
Pollination
A
The transfer of pollen from the male part of a flower to the female part of another flower
13
Q
Plants that rely on insects for pollination
A
Insect-pollinated
14
Q
Male part of a plant
A
Stamen - anther & filament
15
Q
Female part of a plant
A
Carpel - ovary, style & stigma
16
Q
Sepal description & function
A
- Green part at the top of the stem under the petals
- Protects the flower when growing and helps to stop it from drying out
17
Q
Petal description & function
A
- Brightly colored part of the flower
- Attract insects, birds or mammals for pollination
18
Q
Stamen description & function
A
- Male part of the flower containing the filament and anther
- Produces male gametes (pollen) and provides needed structures and conditions for pollen transfer
19
Q
Filament description & function
A
- There stalk that supports the anther
- Holds the anther in position to transfer pollen to a pollinator
20
Q
Anther description & function
A
- Colored, usually with a powdery appearance
- Produces pollen grains which contain the plant’s male gametes
21
Q
Stigma description & function
A
- Usually green and the tallest part inside the flower with a sticky layer
- Traps pollen from other flowers
22
Q
Style description & function
A
- Thin structure that supports the stigma and is above the ovary
- Supports and presents the stigma in a position to receive pollen
23
Q
Carpel description & function
A
- Female part of the flower that contains the stigma, style & ovary
- Produces female gametes and provides correct structures and conditions for fertilization
24
Q
Ovary description & function
A
- Green, bulb-shaped part near the bottom of the flower
- Contains ovules (containing female gametes), which will develop into seeds after fertilization
25
Ovule description & function
- Structures within the ovary
- Female gametes are produced and contained in the ovules which will then become seeds upon fertilization
26
Pollen transported by insects
- Spiky outer layer
- Hooks onto insects
27
Pollen transported by wind
- Smaller, lighter & smoother than insect pollen
28
Self-pollination
The transfer of pollen grains from the anther of a flower to the stigma of the same flower or to a different flower of the same plant
29
Advantages of self-pollination
- Plants don't have to rely on pollinators like insects
- Plants can grow where pollinators don't exist
30
Disadvantages of self-pollination
- Reduces variation within the population
- Increases vulnerability to environmental changes and disease
31
Cross-pollination
The transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant of the same species
32
Advantages of cross-pollination
- Increases variation within the population
- Reduces vulnerability to environmental changes and disease
33
Disadvantages of cross-pollination
- Relies on pollinators to transport the pollen from one plant to another
34
Petals of wind-pollinated flowers
- Small and usually dull in color due to a lack of needing to attract insects
35
Petals of insect-pollinated flowers
- Large and brightly colored to attract insect pollinators
36
Anthers of wind-pollinated flowers
- Loosely attached and dance outside the flower so pollen can be blown by wind
37
Anthers of insect-pollinated flowers
- Located inside the flower to brush against insects
38
Stigma of a wind-pollinated flower
- Loosely attached and dangle outside the flower to catch wind-borne pollen - feathery
39
Stigma of a insect-pollinated flower
- Located inside the flower to brush against insects
40
Difference of nectar in insect & wind pollinated flowers
- Nectar is produced in insect-pollinated flowers but not in wind-pollinated flowers
41
Fertilization
When a pollen nucleus fuses with a nucleus in an ovule
42
How fertilization happens after pollination
- Pollen the grows through the style to the ovary
- Two male gametes move through the tube and reach an ovule
- One nucleus of the two sperm cells fuses with the egg cell
- Zygote forms and develops into an embryo
43
Germination
The process by which a plant grows from a seed
44
Needs of germination
- Water
- Oxygen
- A suitable temperature
45
Function of the testicles
Organ in which sperm cells and testosterone are produced
46
Function of the scrotum
A sack of skin that contains the testicles, helping to keep them at a slightly lower temperature than the rest of the body
47
Function of the prostate gland
Secretes fluid that nourished and protects sperm - mixture of liquid and sperm is semen
48
Function of the sperm duct
Muscular tube that connects the testicles to the urethra
49
Function of the urethra
Tube that allows the passage of semen and urine through the center of the penis
50
Function of the penis
During sexual intercourse, the penis is inserted into the vagina, allowing sperm to transfer into the female reproductive system
51
Function of the ovaries
To produce egg cells and the horses estrogen and progesterone
52
Function of the oviducts/fallopian tubes
Tubes connecting ovaries to the uterus, fertilization occurs here
53
Function of the uterus
Organ in which the embryo develops
54
Function of the cervix
Ring of muscle between the vagina and the uterus
55
Function of the vagina
Elastic muscular canal that a newborn passes through during childbirth & where a male's penis is inserted in intercourse
56
Fertilization in humans
The fusion of the nucleus of a male gamete/sperm and the nucleus of a female gamete/egg to form a zygote
57
Structure of a sperm
- Three parts: head, midpiece, flagellum
58
Acrosome
- Tip of a sperm head
- Secretes digestive enzymes that allow the sperm to pass through the jelly coating of the surface of an egg cell
59
Flagellum
- Tail that lets the sperm cell move/propel the cell from one place to another
60
Midpiece of sperm
- Contains mitochondria
- Release energy by respiration to help keep the flagellum moving
61
Nucleus of an egg cell
- Contains the mother's DNA which will fuse with the father's
62
Cytoplasm of an egg cell
- Contains energy stores to allow the egg to survive several of days and to nourish the zygote if fertilization occurs into the implant in the wall of the uterus
63
Jelly coat of an egg cell
- Allows sperm to attach
- Creates a barrier from other sperm cells attaching one one has penetrated and entered the cell
64
Follicular cells of an egg cell
- Follicle cells attached to the egg to help nourish the egg in its journey
65
Size comparison of an egg and sperm cell
- Diameter of an egg cell is 0.1mm
- Diameter of a sperm cell is 0.05mm
66
Number comparison of egg and sperm cells
- Female usually releases only one egg cell each month
- Male can release 40M to 1.2B sperm in a single ejaculation
67
Motility comparison of egg and sperm cells
- Egg cells can't move on their own
- Sperm cells can move 1-3mm an hour
68
Timing after fertilization before the embryo implants in the uterus wall
five days
69
Timing between how long it takes for an embryo to become a fetus
8 weeks
70
Function of the placenta
- Transfers substances from the mother to the fetus
- Transfers waste substances from the fetus to the mother so her body can excrete them
- Barrier against toxins and pathogens the mother is exposed to (except for nicotine and other pathogens)
71
Amniotic sac
- Protective layer for the fetus
- Full of amniotic fluid that contains nutrients needed by the fetus
72
Umbilical cord
Attached the fetus to the placenta
73
Exchange of materials between the fetus and placenta
- Placenta provides oxygen, carbohydrates, proteins, fats, vitamins, minerals and water to grow
- Fetus produces waste products such as carbon dioxide and urea
- Blood of mother diffuses through capillaries between the placenta and umbilical cord
74
Puberty
When a child's body begins to change into an adult's body
75
Surge of male sex hormone in puberty
Testosterone
76
Surge of female sex hormone in puberty
Estrogen
77
Changes during puberty for males
- Facial hair
- Shoulders get wider
- Voice deepens, voice box/Adam's apple enlarges
- Hair under the arms
- Pubic hairs
- Penis and testicles grow larger
78
Changes during puberty for females
- Breasts start to develop
- Hair under the arms
- Pubic hairs
- Hip bones widen
79
Frequency of eggs cells being released from ovaries
- Once every 4 weeks (28 days)
- Or anything between 21-40 days
80
Ovulation
- When the egg is released from the follicle
- Happens around day 14
- After ovulation the follicle develops into corpus luteum
81
Lining of the uterus in the menstrual cycle
- From day 4 the lining of the uterus thickens so the egg can implant if fertilized
- If the egg is not fertilized the lining breaks down and is discharged as menstrual fluid (blood and other materials from the lining) - known as a period
82
Duration of a period
- Few days to a week
83
Four hormones in control of the menstrual cycle
- Follicle-stimulating hormone (FSH)
- Luteinising hormone (LH)
- Estrogen
- Progesterone
84
Where the four hormones of the menstrual cycle are secreted
- Estrogen - Ovary
- Progesterone - Corpus luteum in an ovary
- FSH & LH - Pituitary gland
85
Effect of FSH in the menstrual cycle
Causes an egg in an ovary to mature
86
Effect of LH in the menstrual cycle
Stimulates the release of a mature egg
87
Effect of estrogen & progesterone in the menstrual cycle
Involved in painting the lining of the uterus
88
How FSH interacts in the menstrual cycle
Stimulates the ovary to secrete estrogen
89
How estrogen & progesterone interact in the menstrual cycle
Inhibit the release of FSH & LH
90
How levels of the four menstrual cycle hormones change
- Start - progesterone is low - releases FSH
- FSH rises - causes egg to mature - stimulates release of estrogen
- Estrogen rises - releases FSH & later LH
- LH rises - releases the mature egg from its follicle at day 14
- Empty follicle become corpus luteum - progesterone produced
- Progesterone rises - Release of FSH & LH
91
Hormones during pregnancy
0 Corpus letup continues to release estrogen and progesterone until week around 8-12 weeks where placenta takes over production of hormones
92
Placenta function with hormone production
- Ensures no more eggs are released
- Maintains thick uterine lining to support growing fetus
- Prevents muscles of uterus from contracting
93
Examples of virus STIs
- Genital warts
- herpes
- HIV
94
STI
Sexually transmitted infection
95
Examples of bacterium STIs
- Chlamydia
- Gonorrhea
- Syphilis
96
Barrier methods for protection
Reduce the chance of coming into contact with infected body fluids
96
Examples of barrier methods
Female & male condoms
96
HIV
Human immunodeficiency virus
97
AIDS
Acquired immune deficiency syndrome
