Answer:
Xylem cells have no cytoplasm or end walls, meaning they form a tube through which water can pass freely to allow water transport. Lignin strengthens the cell walls, helping to support the plant.
The answer would be adaption or evolution in the animal kingdom
Answer:
The correct option is Number 1. AaBb x AaBb
Explanation:
Genes can be described as basic hereditary units. The genes are made up of DNA.
A gene carries two alleles for a particular trait. These alleles are present at the same loci in the homologous chromosomes. If the two alleles are similar then they are termed as homozygous e.g AA, BB. If the alleles for a trait are different then they are termed as heterozygous e.g Aa and Bb.
D. a viral disease because it is known and unknown and spreads.