Multicellular Organisms Part II Flashcards
(35 cards)
What is continuous variation
Continuous variation describes a characteristic of an animal or plant that shows a range of values between a minimum and maximum value
What are the examples of continuous variation
Height Leaf length Tail length in mice Hand span Shell diameter
What is discrete variation
Discrete variation describes a characteristic that can be separated into distinct categories.
What are the examples of discrete variation
Finger print Earlobe shape Tongue rolling ability Blood group Eye colour
What is an allele ?
Alleles are different forms of genes.
Finish this sentence
During gamete formation the chromosomes are reduced to a …
Single set
What is a genotype
The set of genes possessed by an organism (always written in letters)
What is dominant ?
The version of a gene that always makes the presence of a recessive allele
What is recessive
The version of a gene that always masked by the dominant allele. Requires two recessive alleles for phenotype to be expressed
What does homozygous mean
A genotype that contains two identical alleles for a particular gene.
What does heterozygous mean
A genotype that contains two different alleles for a particular gene
What does true breeding mean
When both parents have homozygous genotypes.
What does polygenic inheritance mean
When a characteristic controlled by the alleles of more than one gene
What does phenotype mean
The appearance of the physical characteristic (e.g. Blue eyes)
What is a xylem
It is a dead cell in plants. It is a hallow tube with rings of lignin. It transports of water and minerals from the soil. Also provides support.
What is a phloem
It transports sugar in all directions in plants. It is a living cell.
What do sieves plates do
They are end walls with pores, which allows rapid transport of sugar.
What do cytoplasm strands do
They help move sugar from one sieve tube to another
What is a cuticle, what is its feature and function
Cuticle - waxy layer, protects and waterproofs
Epidermis, what is its feature and function
Epidermis - close fitting cells, it protects
Mesophyll, what is its feature and function
Mesophyll - contain many chloroplasts, major site of photosynthesis.
Vein, what is its feature and function
Tubes made of xylem & phloem, transport water & sugar
Guard cell, what is its feature and function
Changes shape, open and close stomata pores.
Stomata, what is its feature and function
Found in the leaf, pore, allows evaporation of water and gas exchange
