Reproduction Flashcards
Sexual Reproduction
Sexual reproduction involves two parents. Gametes, or sex cells, are produced in reproductive organsby meiosis (see page 147). A male and a female gamete fuse during fertilisation to form a single cell called a zygote. The zygote divides by mitosis to form an embryo and ultimately an foetus. Offspringproduced sexually receive genes from both parents, thereforethey possess characteristics of bothparents, i.e. they show variation.
Reproduction
the process by whichliving organisms generate new individuals of the same kindas themselves.
Asexual Reproduction
involves only one parent and offspring are produced bymitosis (see page 145). All offspring produced asexually from one parent aregenetically identical and are collectively calleda clone. Asexual reproduction is conservative because it conserves the characteristics of the parent. Certain plants as well as fungi and unicellular organisms, e.g. amoeba and bacteria, reproduce asexually
Binary Fission
Binary Fission is what happens when an organism duplicates its genetic material/DNA and creates an offspring. It is the separation of one body into two.
Budding
When a new organism is developed by a bud or outgrowth from their parent organism. This is due to cell division.
Organisms that reproduce asexually are:
Spider Plants- they make clones of themselves
Bacteria- Binary Fission
Hydra- Budding
Archea
fungi
potatoes
turkey
Asexual Reproduction:
Advantages
Disadvantages
Not energy consuming (as you don’t need a mate).
Fast, not time consuming.
Population has the potential to rapidly increase (depends on the conditions).
Only one organism needed.
No genetic variation/diversity.
Population increase can be uncontrollable.
Since ways to asexually reproduce like Binary Fission literally copy the parent organism’s DNA to create and offspring, there’s no genetic variation/diversity therefore if one ‘clone’ contracts a disease, it’s more than likely all will; resulting in widespread death.
Low chance of adaptation to new conditions or environments.
Sexual Reproduction
This involves the bringing together or fusion of reproductive cells called GAMETES. One of these is from the female and the other is from the male.
The female gamete is called the ovum or egg, and the male gamete is called the sperm.
Sexual Reproduction
Advantages
Disadvantages
Genetic Variation/Diversity
Population increase can be/has the potential to be controlled
High chance of adaptation to new condition or environment
Diseases are less likely to affect the entire population
Time consuming Energy consuming ( as you need to find a mate) Slow population increase due to a variety of factors for example, infertility.
Why is sexual reproduction important?
Sexual reproduction is important for genetic variation. When 2 organisms are needed to reproduce, their chromosomes (genetic material) are brought together creating variation in their offspring/offsprings.
What are Gametes?
Gametes are reproductive cells. The sperm being the male gamete and the ovum being the female gamete. The female and male gametes differ from one other due to a process called meiosis.
Puberty
Puberty is the development of secondary sexual characteristics.
Hormones that enable/trigger puberty:
Testosterone for the males which is produced in the testes.
Oestrogen for females which is produced in the ovaries.
Puberty in Males and Females
Growth spurt Hair Growth- genital area, underarms, legs Increased oil production in skin Hormonal Change Mood Swings
Males Broadening of shoulders Facial Hair Deepening Of voice Sperm production
Females Menstruation Hips widening Bust/Breast development Increase in vaginal discharge
CToso- cells, tissues, organs, systems and organisms
a cell is said to be specialized when it is modified to carry out a particular function like a muscle cell being adapted for contraction or xylem vessel for transport in plants.
specialized cells usually don’t function on their own so they group together forming tissues.
tissues are groups of specialized cells who work together to perform a particular function
organs are several types of tissues who are grouped together in a single structure to perform a particular task.
organisms are a series of organs whose functions are co-ordinated to carry out a particular function
Female reproductive system- uterus
The uterus is where a fetus, or baby, grows. It is a hollow, pear‑shaped organ with a muscular wall.
ovaries
there are two on either side of the uterus
oval shaped
Ovaries make eggs and hormones like estrogen and progesterone. These hormones help girls develop, and make it possible for a woman to have a baby.
oviducts or Fallopian tube
Fallopian tubes go from the uterus to the ovaries. where the ovum is released during ovulation
upper corners of uterus
cervix
The cervix is the lower part of the uterus that opens into the vagina. it is called the neck of the female reproductive system
strong thick walls
vagina
The vagina is a muscular tube that connects the uterus to the outside of the body.
uterus wall
able to contract and expand to accommodate a growing foetus and later help in the deliverance
male reproductive system- seminal vesicles
Located at the base of the bladder, the two seminal vesicles secrete a thick fluid that nourishes the sperm.
bladder
The bladder is the muscular sac that stores urine (pee) until it is released through the urethra.
prostate gland
This walnut-sized gland surrounds a portion of the urethra and produces some of the fluid in semen.
vas deferens
thin muscular tube transports the sperm from the epididymis to the urethra.
urethra
the tube that carries semen and urine out of the penis.
scrotal sac or scrotum
hangs under the penis and contains the testicles and epididymis.
penis
has two parts, during sexual intercourse it becomes erect
The penis delivers sperm through the urethra.
testes or testicles
produce sperm and the male sex hormone testosterone.
epididymis
Next to each testicle, the epididymis is a light-colored tube where sperm is stored. From here, sperm are transported to the vas deferens.
erectile tissue
any tissue that is capable of stiffening or engorging with blood. during sexual intercourse the penis is enlarged and becomes erect.
pathway along which sperm travels
testes epididymis sperm duct/vas deferens urethra
