Which statement is true about a person's chromosomes? 1: they are all identical

2: their sister chromatids are joined at centrosomes

3: they are arranged in homologous groups of three

4: they are long chains of DNA

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?

Which of the following particles always has a positive charge? a. electronb. neutron c. proton d. ion

Which genetic disorders, caused by an extra x chromosome (xxy), is characterized by a lack of testicular development in males, effeminate features, possible mental impairment, and a thin stature?