Answer: different organisms have different chromosome numbers
Explanation: eukaryote cells have more than one chromosome
chromosomes are present in most cells all the time (not in erythrocytes), but cannot be visualised except during telophase of mitosis or meisosis
bacterial cells don’t have a nucleus
Answer:
Answer is option A.
Orchid bees are to Brazil nut trees as breezes are to pine trees.
Explanation:
In Brazil nut trees, the female orchid bees act as pollinators that help in pollination. In pine trees, wind or breeze helps in pollination.
Pine trees are gymnosperms and so they do not have flowers to attract pollinators like bees or butterflies or birds. They are wind-pollinated. Pine trees are monoecious i.e., both male and female reproductive structures (pine cones) are present on the same tree.
The male cones (catkins) produce pollen grains that are lightweight, less sticky and have air bladders or small wing-like structures. As a result of these features, the pollen grains can be easily carried and dispersed by the breeze. In order to prevent self pollination (pollen falling on the female cones of the same tree), the male cones are normally located on the lower branches of the pine tree.
The female cones are located on the upper branches of the tree and the center of the cone contains eggs or ovules. The pollen grains that are carried by the wind, fall on the female cone of another pine tree. Each pollen grain grows a pollen tube into the center of the cone and the nucleus cell of the pollen travels through the tube and reaches the egg, where it combines with the egg to form an embryo. The embryo eventually grows into a seed. The seeds of pine trees are then dispersed by wind or animals such as squirrels.
Answer: DNA contains alternating sugar-phosphate molecules whereas RNA does not contain sugars
Explanation:
Answer:
Mitosis, Meiosis, and both are written below
Explanation:
Mitosis: produces more somatic (body) cells, purpose is for healing and growing, the daughter cells are exact replicas
- This is because mitosis occurs in body cells and is used for growth, so all the daughter cells are the same.
Meiosis: results in sex cells (gametes), results in eggs and sperm, purpose is for creating new individuals (eventually), each daughter cell is different, has 2 separate division stages
- This is because meiosis occurs in gametes and is used in reproduction.
Both: Chromosomes need to replicate before the whole process begins, a form of reproduction
- This is because both are reproducing (they are dividing) and DNA must be replicated so each daughter cell has it.
Answer: A- cell wall
A new cell wall forms between the two membranes of the cell plate.
