SCIENCE REPRODUCTION Flashcards
WHAT IS ASEXUAL REPRODUCTION
Asexual reproduction is where an organism creates an offspring with identical DNA to itself without a partner.
ONE PARENT
Organisms produce offspring without fertilisation
WHAT IS BINARY FISSION AND GIVE EXAMPLE
Binary fission is when a parent cell divides itself into 2 equal, identical cells with the same DNA. Example= Bacteria
UNIFORM-OFFSPRING
Because the offspring inherit all their DNA from one parent they are genetically identical to each other and to their parent
WHAT IS BUDDING GIVE AN EXAMPLE
Budding is when new individuals develop as outgrowths or buds from the parents body. Eg= yeast
WHAT IS SPORES GIVE AN EXAMPLE
Each spore is mobile and when released from the parents organism it develops into a new organism exactly like the parent. Eg= fungi
WHAT IS VEGETATIVE PROPAGATION GIVE EXAMPLE
Vegetative propagation is the non-sexual parts of the plant that are used to grown new individuals of the same type. Eg) Potatoes
WHAT IS PARTHENOGENESIS GIVE AN EXAMPLE
Occurs when unfertilized eggs develop into offspring. Eg= bees
WHAT IS FRAGMENTATION AND GIVE AN EXAMPLE
Fragmentation is when the parent organism can be divided into many pieces and each piece will develop into a complete individual. Eg= Starfish
ADVANTAGES OF ASEXUAL REPRODUCTION
- Less time and energy
- Easy dispersal
- More off spring
DISADVANTAGES OF ASEXUAL REPRODUCTION
- Mutations in DNA
- No variation
- Disease
- Environmental Conditions
WHAT IS SEXUAL REPRODUCTION
Sexual reproduction is when the genetic materials from the male and female cells combine during fertilisation to produce and offspring which is genetically different to its parents. The cells that combine are called gametes(sex cells)
WHAT ARE THE MALE AND FEMALE GAMETES
Female: egg also known as ova/ovum
Male: sperm
WHAT IS FERTILIZATION
An egg cell and sperm cell join together to form a new cell called a zygote. Sperm must meet the egg in the fallopian tube for fertilization
WHAT IS A ZYGOTE
A fertilised egg
WHAT IS INTERNAL FERTILISATION
Occurs when the male sperm fuses with the female eggs inside the female body. Found in mammals,birds,reptiles
WHAT IS EXTERNAL FERTILISATION
Occurs when the male sperm and female eggs unite outside the females body. Occurs in fish
WHAT ARE HERMAPHRODITES
They are organisms that have both male and female reproductive systems, they may self-fertilize or mate with someone,fertilizing each other and both producing offspring. Occurs in fish
Self-fertilisation is common in animals with limited mobility.
Snails and tapeworms are hermaphrodites meaning they can produce both sperm and egg cells.
ADVANTAGES OF SEXUAL REPRODUCTION
- Variation
- Able to cope when changes occur
- Difference allows a greater chance of survival for the species
DISADVANTAGES OF SEXUAL REPRODUCTION
- Time and energy
- Organisms have to grow until they are old enough to produce sex cells
- Fertilisation cannot take place during pregnancy.
WHERE ARE MALE GAMETES FOUND IN FLOWERING PLANTS
Pollen grains and produced in the anthers of the flower
WHERE ARE THE FEMALE GAMETES FOUND IN FLOWERING PLANTS
ovules and produced in the ovary of the flower
WHAT ARE SEPALS
Sepals= protect the unopened flower bud
WHAT ARE PETALS
Petals= May be bright coloured and scented to attract insects
WHAT IS THE STAMEN
Stamen= male parts of the flower consisting of the anther held up on the filament
WHAT IS THE ANTHER
Anther= produces male gametes(in pollen grains.
The anther and filament are the male parts of a flower
WHAT IS THE FILAMENT
Filament= Thread-like part of a stamen that supports the anther of a flower(male part with anther)
WHAT IS THE CARPEL
Carpel= Female parts of a flower consisting of the stigma,style and ovary
WHAT IS THE STIGMA
Stigma= The top of the female part of a flower which collects pollen grains.
WHAT IS THE STYLE
Long stalk that connects the stigma and ovary and also where the male gamete travels to reach the ovary.